1. Field of the Invention
The present invention relates to a link plate for a silent chain, and more particularly, to an improvement of structure to decrease noise of the silent chain during operation.
2. Description of Related Art
A silent chain is generally constructed from a plurality of link plates each having a pair of teeth and pin apertures and arranged in lateral and longitudinal directions and joined pivotably by connecting pins.
There are various frequencies in noise that occurs during operation of a silent chain. In these frequencies, a frequency having the greatest intensity forms a so-called primary oscillation of engagement. Since such primary oscillation of engagement gives objectionable impression to ears of human beings, various efforts and improvements have been made to decrease the primary oscillation of engagement.
Referring to FIG. 6, the around-the-pin moment will be explained. FIG. 6 shows a state of engagement of a link plate in a specified row of a silent chain with a sprocket teeth. A link plate 100 is engaged with a sprocket 200 rotating in an arrow mark direction. The link plate 100 includes a pair of teeth 110 and pin apertures 120 having pins 130 inserted thereinto. Each of the teeth 110 is formed of an inside flank 111 and an outside flank 112. A tooth 210 of the sprocket 200 is in contact with the outside flank 112 of one of the teeth 110 of the link plate 100.
In such a state of engagement, tension T is applied to each row of link plates forming a silent chain. On the other hand, force F from the sprocket tooth 210 is applied to an engagement point 112e on the outside flank 112 of the link plate 100. When a length of a perpendicular drawn from a center of a pin aperture to an action line of the force F is L, a moment M around a pin is shown by M=F×L.